Video splitter design

[kristaps_r]

Hi guys,

I am trying to integrate video splitter in my hobby project. I have studied one splitter available and draw schematic of it.
I have soldered this circuit but it is not working. Can you guys look at circuit. Maybe I draw it incorrect. I am dumb in analog electronics and transistors.
Should it work?

VCC is 5V

 

[chuckey]

You have left out the bias components that allow the transistors to conduct a little current. Try connecting a 10K resistor between the base of one transistor and ground. If you have a meter measure the voltage drop across the emitter resistors, it should be about 2V, if its less then reduce the resistor value. If the transistors start to get hot, increase the value. With such a simple circuit there will be a compromise between overloading the transistors so your video is clipped and over heating the transistors because they are drawing too much current.
Frank

 

[kristaps_r]

Thank you for your fast reply. I will try 10k to GND.
You mentioned about simple circuit I have found also this little more complicated circuit but it works on 9V: https://forum.tsebi.com/viewtopic.php?f=4&t=23#p248
Is it better in some way?
I prefer 5V voltage. Maybe you know some simple enough video splitter circuits that will run efficient on 5V without issues like overheating?

- - - Updated - - -

I forgot to ask also is it important what transistors I am using in these circuits?
Sorry if it is dumb question

 

[schmitt trigger]

Check figure 8 of the following document:

http://cds.linear.com/docs/en/application-note/an57fa.pdf

 

[kristaps_r]

Thanks.
I will look also for 3 channel version.